FATTY ACID SIGNATURES DIFFERENTIATE MARINE MACROPHYTES AT ORDINAL AND FAMILY RANKS1

Primary productivity by plants and algae is the fundamental source of energy in virtually all food webs. Furthermore, photosynthetic organisms are the sole source for ω‐3 and ω‐6 essential fatty acids (EFA) to upper trophic levels. Because animals cannot synthesize EFA, these molecules may be useful as trophic markers for tracking sources of primary production through food webs if different primary producer groups have different EFA signatures. We tested the hypothesis that different marine macrophyte groups have distinct fatty acid (FA) signatures by conducting a phylogenetic survey of 40 marine macrophytes (seaweeds and seagrasses) representing 36 families, 21 orders, and four phyla in the San Juan Archipelago, WA, USA. We used multivariate statistics to show that FA composition differed significantly (P < 0.001) among phyla, orders, and families using 44 FA and a subset of seven EFA (P < 0.001). A second analysis of published EFA data of 123 additional macrophytes confirmed that this pattern was robust on a global scale (P < 0.001). This phylogenetic differentiation of macrophyte taxa shows a clear relationship between macrophyte phylogeny and FA content and strongly suggests that FA signature analyses can offer a viable approach to clarifying fundamental questions about the contribution of different basal resources to food webs. Moreover, these results imply that taxa with commercially valuable EFA signatures will likely share such characteristics with other closely related taxa that have not yet been evaluated for FA content.     

SYNOPSIS OF THE GENERA OF AUSTRALIAN HETERONYCINI (COLEOPTERA: SCARABAEIDAE: MELOLONTHINAE)

Abstract
The tribe Heteronycini and 10 included genera (4 of them new) are defined. A key to genera and keys to species of Acheilo gen. n. and Webbella gen. n. are provided. The new genera are: Acheilo, Paraheteronyx, Proborhinus and Webbella. A. clypeatus gen. n., sp. n. is described.
The following species are transferred to other genera: Heteronyx bravicollis Blackburn, H. brevicoxis Lea, H. clypealis Lea, H. cribrifrons Lea, H. inconstans Lea, H. noctivagus Lea, H. phanophilus Lea, H. transversopolitus Lea and H. unidentatus Lea to Neoheteronyx Blackburn; H. unguiculatus Burmeister to Paraheteronyx gen. n.; H. cornutus Blackburn to Proborhinus gen. n.; H. capitalis Blackburn and H. pedarius Blackburn to Acheilo gen. n.; H. firmus Blackburn and H. labralis Blackburn to Webbella gen. n. Anacheirotus Blackburn is synonymised with Heteronyx Guérin-Méneville; A. inornatus Blackburn becomes H. inornatus (Blackburn). Pseudoheteronyx seticollis Lea is synonymised with P. creber Blackburn. Heteronyx clypealis Lea is synonymised with Neoheteronyx brevicollis (Blackburn). Lectotypes are designated for Heteronyx unguiculatus and Eurychelus marmoratus Blanchard.     

The concentration and composition of big sagebrush essential oils from Oregon

The concentration of essential oils in big sagebrush foliage, Artemisia tridentata subsp. tridentata, subsp. vaseyana and subsp. wyomingensis collected from Oregon, differed significantly between individual shrubs with no correlation to geographic site, subspecies genotype, or plant age. Essential oil composition, measured by headspace analysis, was not affected by plant age, location of tissue within the crown, or geographic site. Six of 16 compounds differed quantitatively by subspecies, with wyomingensis and tridentata having nearly the same composition. Vaseyana could be recognized by its significantly lower concentration of acetone and methacrolein, two highly volatile, non-terpenoid, constituents. The implication of these results and those of recent studies are discussed in relation to herbivory.     

Radiolabeled octreotide

Octreotide is a synthetic analog of the peptide hormone somatostatin (SMS). A wide variety of tumors express enhanced numbers of SMS receptors, notably neuroendocrine tumors and lymphomas, but also some of the more common adenocarcinomas. Octreotide contains only eight amino acids, some of which are in the (D) configuration in order to enhance the stability of the molecule in vivo. Tyrosine and ATPA-containing analogs of octreotide have been synthesized and labeled with iodine-123 and indium-111, respectively, with the intention of targeting SMS receptor-containing tumors for diagnostic purposes. Both radiopharmaceuticals demonstrate a high sensitivity and specificity for these tumors, indicating a clinical role for these agents in management of these diseases. Lessons can be learned from the success of these agents when designing improved antibody-based molecules. Tumor uptake of radiolabeled octreotide is very rapid, occurring within minutes of administration. Blood clearance is also rapid, such that tumors are soon visible even in areas of high blood background. An interesting finding has been the differences between the pharmacokinetics of the iodinated and indium-labeled species. Although the majority of¹²³I-Tyr³-octreotide undergoes hepatobiliary excretion,¹¹¹In-DTPAPhe¹-octreotide is eliminated predominantly by the kidneys. These results suggest that the smallest possible antibody-like tracers are likely to have advantages over native immunoglobulins and conventionals Fab-like fragments.     

The effect of carbon monoxide on haem-facilitated oxygen diffusion

The aim of this paper is to quantify the effect of small quantities of carbon monoxide on the facilitated diffusion of oxygen by haemoglobin in the steady state. It is the first phase in the study of a mathematical model for carbon monoxide poisoning. Here we extend the Wyman model for facilitated diffusion to the case in which there are two ligands. The equations are solved using an asymptotic technique developed by Murray. We obtain accurate analytic approximations for the biologically important quantities of the problem for various percentages of carbon monoxide. These are the concentrations of free oxygen, haemoglobin, oxyhaemoglobin and carboxyhaemoglobin, and hence the saturation of the protein and the facilitated oxygen flux. The major effect of very small quantities of carbon monoxide on the oxygen flux is shown.